<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<script src="https://cdn.jsdelivr.net/npm/vue@2.6.12"></script>
	</head>
	<style>
		a{
			text-decoration: none;
			color: black;
		}
		.yy{
			border: 1px solid pink;
			color: #008000;
		}
		.large{
			font-size: 2em;
		}
	</style>
	<body>
		<div id="app">
			<nav>
				<a href="#" v-bind:class="[{yy:isYY},largeClass]">多喝热水</a>
			</nav>
		</div>
		<script>
			let app =new Vue({
				el:"#app",
				data:{
					isYY:true,
					largeClass:"large"
				}
			});
			
		</script>
	</body>
</html>
